# How to write an equation for a parabola  Standard and vertex form of the equation of parabola and how it relates. Play as Sakura and use your charms to make either Naruto, Sasuke or Rock Lee fall in love with you! The vertex form of a parabola's equation is generally expressed as y = ax-h 2 +k. h,k is the vertex as you can see in the picture below. If a is positive then the parabola opens upwards like a regular "U". If a is negative, then the graph opens downwards like an upside down "U". Equation of a parabola from focus & directrix video Khan. Visit various locations from the series, meet new characters and decide your activities for the day. The equation of a parabola is derived from the focus and directrix, and then the general formula is used to solve an example. How to Find Equation of a Parabola Sciencing Indeed, prior research naruto and sakura dating date has shown that americans are wary when it comes to the holiday. The easiest way to find the equation of a parabola is by using your knowledge of a special point, called the vertex, which is located on the parabola itself. Recognizing a Parabola Formula If you see a quadratic equation in two variables, of the form y = ax 2 + bx + c, where a ≠ 0, then congratulations!